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#2
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dynamic range
Paul Furman wrote:
Could there be a filter to increase dynamic range? Kinda like a polarizer that blocks bright light while letting in dim shadow detail? As I understand, whatever the camera is capable of capturing before the highlights blow is squeezed into the same file format between black & white so a high DR camera is actually going to be a bit less contrasty. Or you can just have the raw converter (or jpeg creation) extract something less contrasty and apply curves to that to put the contrast where it's desired... but even then, I sometimes have to do multiple raw conversions to recover blown highlights. |
#3
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dynamic range
"Paul Furman" wrote in message t... Paul Furman wrote: Could there be a filter to increase dynamic range? Kinda like a polarizer that blocks bright light while letting in dim shadow detail? As I understand, whatever the camera is capable of capturing before the highlights blow is squeezed into the same file format between black & white so a high DR camera is actually going to be a bit less contrasty. Or you can just have the raw converter (or jpeg creation) extract something less contrasty and apply curves to that to put the contrast where it's desired... but even then, I sometimes have to do multiple raw conversions to recover blown highlights. No filter can increase dynamic range unless one is willing to expand the range after the fact of a limited/filtered selection. Kind of a cheat, by the way. You can initially clip the dynamic range and then later expand it. So, my answer is basically NO. This could be an interesting thread! |
#4
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dynamic range
"Paul Furman" wrote in message t... Could there be a filter to increase dynamic range? Not a filter, it would add its own 1-2% reduction (assuming quality coating on all lens groups). A well configured lens hood *will* increase Dynamic range, especially if the lens isn't spotless clean. Bart |
#5
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dynamic range
"Paul Furman" schreef in bericht t... Could there be a filter to increase dynamic range? Kinda like a polarizer that blocks bright light while letting in dim shadow detail? As I understand, whatever the camera is capable of capturing before the highlights blow is squeezed into the same file format between black & white so a high DR camera is actually going to be a bit less contrasty. What are the DR ratings for various DSLRs? There are filters which in some circumstances make a picture less contrasty. That would mean that in those circumstances you actually can record a scene with more dynamic range. Later on you can use part of the dynamic range to get the picture you actualy want, or you can stretch the dynamic range to obtain a dynamic range which represents the reality a bit more. I do not now how to make such dynamic range visible though. (Not on screen, not on paper). And I don't think that filters which reduce the contrast will improve the picture. ben brugman |
#6
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dynamic range
"Paul Furman" wrote in message t... SNIP What are the DR ratings for various DSLRs? They can/could extend to the full 12-bit (4095:1) range that the DSLR's ADC provides, give or take half a bit quantization error. Boosting that to the 32767:1 or 65535:1 working space range will help to allow for post-processing rounding errors, before reducing that to the 126:1 printing range. Bart |
#7
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dynamic range
In message ,
"Charles Schuler" wrote: No filter can increase dynamic range unless one is willing to expand the range after the fact of a limited/filtered selection. Kind of a cheat, by the way. You can initially clip the dynamic range and then later expand it. So, my answer is basically NO. This could be an interesting thread! Are you talking about something like the Tiffen "ultra contrast" filters? I played with that idea a while back, and my conclusion was that all it basically did was raise the blackpoint of the RAW data, while decreasing the effective subject exposure, so in effect, it basically increased exposure latitude at the expense of exposure strength, and did not increase DR at all (it actually reduced it). It is probably more useful with film, or in lifting the shadows in camera JPEGs, than material for RAW conversion. -- John P Sheehy |
#8
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dynamic range
Bart van der Wolf wrote:
"Paul Furman" wrote in message t... Could there be a filter to increase dynamic range? Not a filter, it would add its own 1-2% reduction (assuming quality coating on all lens groups). A well configured lens hood *will* increase Dynamic range, especially if the lens isn't spotless clean. Ben's contrast reducing filter is something I hadn't heard of, a little googling suggests that tends to give a milky look similar to well controlled flare. That suggests that a lens hood increases contrast which is more likely to blow highlights & leave shadows buried. filters: http://www.tiffen.com/userimages/Con...ctSheet_Lo.pdf discussion: http://www.photo.net/bboard/q-and-a-...id=000F7D&tag= |
#9
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dynamic range
I don't know about a filter but I know when using camera raw in
photoshop to open a raw image, you can alter the contrast which results in more detail in shadows and (provided it is there in the first place) highlights. It makes for a very flat looking picture but one which can have it's attenuation increased with other tools to liven up the image. My experience has been that under exposing when bright objects are present by up to 2 stops allows you to use Photoshop tools the lighten the dark areas while keeping the highlights under control. This also results in flat looking pictures. I think that until the sensors can capture a wider range of detail - maybe closer to human vision - no digital camera and no filter will produce a pleasant looking picture with the full range of such scenes as would normally have blown highlights and blacked shadows. Maddy |
#10
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dynamic range
wrote:
Are you talking about something like the Tiffen "ultra contrast" filters? I played with that idea a while back, and my conclusion was that all it basically did was raise the blackpoint of the RAW data, while decreasing the effective subject exposure, so in effect, it basically increased exposure latitude at the expense of exposure strength, and did not increase DR at all (it actually reduced it). It is probably more useful with film, or in lifting the shadows in camera JPEGs, than material for RAW conversion. It seems to be the same idea as "flashing" paper (or film) in the darkroom to raise the black level out of the bottom of the "toe" of the response curve. That would seem to be inapplicable to RAW capture. -- Jeremy | |
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